The invention relates to a vehicle seat with an adjusting mechanism, for example with a height adjustment of the seat area or with a length adjustment of a longitudinal guiding, whereas the adjusting mechanism is provided with an electromotor, a step-down gear and an adjusting device having a first adjusting element as well as a second adjusting element which may be adjusted relative to the first adjusting element.
Vehicle seats with one or several adjusting mechanisms are state of the art. They make it possible to achieve an ergonomic adjustment of the vehicle seat and are thus contributing to safety. Compared to mechanical adjusting mechanisms they may particularly be adjusted in a more comfortable way that requires less effort. This makes them more comfortable to use.
Generally, a problem arises with these adjusting mechanisms. In the normal operating state of the vehicle seat, either in positive or negative accelerations in or across the driving direction or under stress, forces are acting between the two adjusting elements and are trying to disarrange them relative to one another. This entails at least small relative movements between the two adjusting elements. A small jerk is thus occasioned that may more or less be felt by the user. It particularly leads to a sound, for example to a click. The object of the invention is to find a remedy hereto.
Generally, the couples of rails of a length adjusting device used to adjust in length the vehicle seat are arranged diagonally to the horizontal plane. As soon as a vehicle seat is loaded with a passenger, relative forces are occurring between the two adjusting elements, in this case between the seat rails and the bottom rails of the length adjusting device. Yet also while driving, for example when braking or taking a curve, forces are trying to move the two adjusting elements relative to one another.
Similar problems arise also with other adjusting mechanisms of a vehicle seat, for example with a height adjustment of the seat, an angle adjustment of the backrest and so on. Here too, relative forces are already occurring under normal driving conditions, as well as when the seat is loaded with a passenger, when driving on a bad surface, and so on.
By an adjusting device with a first and a second adjusting element the following is meant: the two adjusting elements are guided mechanically relative to one another, they are for example linked to each other or may be longitudinally displaced relative to one another. Additionally, they are provided with driving parts as for example a pinion pertaining to the first adjusting element and a toothed rack pertaining to the second adjusting element, or, in the same way, a spindle and a spindle nut and so on. The adjusting device thus comprises the parts that have to be mechanically adjusted relative to one another as well as the driving parts for this mechanical adjustment.